Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 2 de 2
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Biol Chem ; 294(45): 16855-16864, 2019 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-31575658

RESUMO

To modulate responses to developmental or environmental cues, plants use Gretchen Hagen 3 (GH3) acyl acid amido synthetases to conjugate an amino acid to a plant hormone, a reaction that regulates free hormone concentration and downstream responses. The model plant Arabidopsis thaliana has 19 GH3 proteins, of which 8 have confirmed biochemical functions. One Brassicaceae-specific clade of GH3 proteins was predicted to use benzoate as a substrate and includes AtGH3.7 and AtGH3.12/PBS3. Previously identified as a 4-hydroxybenzoic acid-glutamate synthetase, AtGH3.12/PBS3 influences pathogen defense responses through salicylic acid. Recent work has shown that AtGH3.12/PBS3 uses isochorismate as a substrate, forming an isochorismate-glutamate conjugate that converts into salicylic acid. Here, we show that AtGH3.7 and AtGH3.12/PBS3 can also conjugate chorismate to cysteine and glutamate, which act as precursors to aromatic amino acids and salicylic acid, respectively. The X-ray crystal structure of AtGH3.12/PBS3 in complex with AMP and chorismate at 1.94 Å resolution, along with site-directed mutagenesis, revealed how the active site potentially accommodates this substrate. Examination of Arabidopsis knockout lines indicated that the gh3.7 mutants do not alter growth and showed no increased susceptibility to the pathogen Pseudomonas syringae, unlike gh3.12 mutants, which were more susceptible than WT plants, as was the gh3.7/gh3.12 double mutant. The findings of our study suggest that GH3 proteins can use metabolic precursors of aromatic amino acids as substrates.


Assuntos
Aminoácidos Aromáticos/metabolismo , Brassicaceae/enzimologia , Ácido Corísmico/metabolismo , Ligases/metabolismo , Ácido Salicílico/metabolismo , Arabidopsis/enzimologia , Domínio Catalítico , Cinética , Ligases/química , Ligases/genética , Modelos Moleculares , Mutação , Especificidade da Espécie , Especificidade por Substrato
2.
Microb Ecol ; 78(2): 470-481, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30666369

RESUMO

Root knot nematodes (RKN, Meloidogyne spp.) are serious pathogens of numerous crops worldwide. Understanding the roles plant rhizosphere soil microbiome play during RKN infection is very important. The current study aims at investigating the impacts of soil microbiome on the activity of RKN. In this study, the 16S rRNA genes of the bacterial communities from nematode-infested and non-infested rhizosphere soils from four different plants were sequenced on the Illumina Hi-Seq platform. The soil microbiome effects on RKN infection were tested in a greenhouse assay. The non-infested soils had more microbial diversity than the infested soils from all plant rhizospheres, and both soil types had exclusive microbial communities. The inoculation of the microbiomes from eggplant and cucumber non-infested soils to tomato plants significantly alleviated the RKN infection, while the microbiome from infested soil showed increased the RKN infection. Furthermore, bacteria Pseudomonas sp. and Bacillus sp. were screened out from non-infested eggplant soil and exhibited biocontrol activity to RKN on tomato. Our findings suggest that microbes may regulate RKN infection in plants and are involved in biocontrol of RKN.


Assuntos
Antibiose , Bactérias/isolamento & purificação , Fenômenos Fisiológicos Bacterianos , Microbiota , Doenças das Plantas/parasitologia , Raízes de Plantas/microbiologia , Solanum lycopersicum/parasitologia , Tylenchoidea/fisiologia , Animais , Bactérias/classificação , Bactérias/genética , DNA Bacteriano/genética , Solanum lycopersicum/microbiologia , Raízes de Plantas/parasitologia , RNA Ribossômico 16S/genética , Rizosfera , Microbiologia do Solo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...